This invention relates to a governor, and more particularly to a governor which is capable of removing dust from working fluid passing therethrough.
An automatic transmission for automobiles consists fundamentally of a torque converter, a transmission assembly and a hydraulic control system. If a hydraulic working fluid circulating through the hydraulic control system contains an appreciable quantity of dust which may comprise steel powder, fine particles of sand and so on, there is a strong possibility of the hydraulic control system functioning inaccurately and, as the most significant problem, various hydraulic control valves in the control system are liable to exhibit malfunction or to become inoperative by reason of sticking.
Every automatic transmission, therefore, uses an oil strainer to remove dust from the working fluid. However, it is practically impossible to trap a very fine portion of the dust by means of an oil strainer (or oil strainers) since there is a limitation to the mesh size of wire screen in the strainer. If the mesh size is made extremely small so that even very fine dust particles may be trapped, the meshes will be clogged in short time during use of the strainer with the result that the working fluid does not smoothly circulate through the hydraulic control system.